Diagnosis
Lupus is a rare disease with diverse, often non-specific symptoms. It can take years to reach a correct diagnosis.
Joint pain or inflammation is the initial symptom in 60% of affected individuals, prompting them to seek medical attention.
Diagnosing Systemic Lupus Erythematosus (SLE) can be challenging, as not all classification criteria are always met at the onset.
Skin changes are the first symptom in approximately 20% of affected individuals.
Diverse Symptoms Complicate Diagnosis
General symptoms such as severe fatigue and fever are often present concurrently and are the primary initial symptom in 5–10% of affected individuals.
In 10–15% of affected individuals, SLE begins with the involvement of internal organs such as the kidneys or the nervous system.
It is crucial that Systemic Lupus Erythematosus is diagnosed as quickly as possible to ensure optimal and timely treatment for affected individuals.
Symptoms and Laboratory Values
The detection of specific antibodies in the blood – antinuclear antibodies (ANA), anti-dsDNA antibodies, anti-Smith antigen antibodies, and anticardiolipin antibodies – can aid in diagnosis.
Other laboratory values also contribute to the diagnosis of SLE: inflammatory markers, decreased complement factors (C3, C4), reduction in leukocytes, lymphocytes, or platelets, etc.
Examination of kidney function parameters, including urinalysis, can also provide indications of SLE.
During a medical consultation, it is important for affected individuals to provide precise information about all their symptoms.
SLE diagnosis typically involves: Clinical examination by the physician, guided by SLE diagnostic criteria. Laboratory tests, which include specific autoantibody determination.
SLE Diagnostic Criteria
The diagnosis of SLE is based on the ACR/EULAR classification criteria.
The new ACR and EULAR classification criteria for lupus from 2019 include positive ANA antibodies as an entry criterion for lupus diagnosis.
Clinical Criteria
Constitutional Symptoms | Points |
|---|---|
Fever | 2 |
Skin | Points |
|---|---|
Non-scarring alopecia | 2 |
Oral ulcers | 2 |
Subacute cutaneous or discoid LE | 4 |
Acute cutaneous LE | 6 |
Arthritis | Points |
|---|---|
Synovitis in ≥ 2 joints or tenderness in ≥ joints with morning stiffness ≥ 30 min | 6 |
Neurology | Points |
|---|---|
Delirium | 2 |
Psychosis | 3 |
Seizures | 5 |
Serositis | Points |
|---|---|
Pleural or pericardial effusion | 5 |
Acute pericarditis | 6 |
Hematology | Points |
|---|---|
Leukopenia | 3 |
Thrombocytopenia | 4 |
Autoimmune hemolysis | 4 |
Kidneys | Points |
|---|---|
Proteinuria ≥ 0.5 g/24h | 4 |
Lupus nephritis (histol.) Type II, V | 8 |
Lupus nephritis (histol.) Type III, IV | 10 |
Immunological Criteria
Antiphospholipid-AK | Points |
|---|---|
Anticardiolipin IgG ≥ 40 GPL | 2 |
Anti-β2GP1 IgG ≥ 40 GPL | 2 |
Lupus anticoagulant | 2 |
Complement | Points |
|---|---|
C3 or C4 decreased | 3 |
C3 and C4 decreased | 4 |
Auto-AK | Points |
|---|---|
Anti-dsDNA-AK | 6 |
Anti-Smith-AK | 6 |
Classification as SLE ANA ≥ 1:80 and ≥ 10 points
ACR/EULAR criteria 2019 for the classification of systemic lupus erythematosus by: Aringer M.: EULAR/ACR classification criteria for SLE. Semin Arthritis Rheum 2019; 49, S14-S17